The study by Carnegie Mellon researchers found that switching to a healthier diet rich in fruit and vegetables and light on meat could actually be worse for the environment.

The results were "counterintuitive" because the fruits, vegetables, dairy and seafood which the USDA guidelines recommend people eat more of have "relatively high resource use and emissions per calorie", the researchers said.

"What is good for us health-wise isn't always what's best for the environment", said study co-author Michelle Tom.

It turns out, as is so often the case, that you're always just better off doing as I do.